股权集中度是股权结构的主要表现形式，为探究股权集中度对股价的影响，采用2003—2020年A股上市公司数据，从非线性视角实证检验了股权集中度对于股价崩盘风险的影响效应及其影响机制。研究发现：股权集中度对股价崩盘风险呈现指数型正向相关关系，股权集中度影响股价崩盘风险过程中同时存在“协同效应”和“掏空效应”，但“掏空效应”占主导地位。此外，在考虑东西部地区异质性、行业异质性和企业异质性差异的情况下，股权集中度对股价崩盘风险影响无显著差异。

Ownership concentration is the main form of ownership structure. In order to explore the impact of ownership concentration on stock price, this paper empirically tests the impact of ownership concentration on stock price crash risk and its influence mechanism from a nonlinear perspective, using the data of A-share listed companies from 2003 to 2020. The results show that ownership concentration has an exponential positive correlation with stock price crash risk, and there are both "synergy effect" and "tunneling effect" in the process of ownership concentration affecting stock price crash risk, but the tunneling effect plays a dominant role. In addition, there is no significant difference in the impact of ownership concentration on the risk of stock price crash considering the eastwest regional heterogeneity, industry heterogeneity and firm heterogeneity.